Improved Skua for FAA?

Macandy · Jul 21, 2022

EwenS said:
Well when your involvement has been limited to the deck operations side of naval aviation for the last 20 years and you have none of the necessary decision making structures in place for deciding what is needed in the future, it is kind of difficult to make immediate changes. Organisational change doesn't happen overnight. Much as you might dislike the notion, change takes time. A new Air Division had to be set up within the Admiralty. New Departments to handle Air Personnel, Air Material (incl aircraft acquisition) and Aircraft Maintenance and Repair.And until you have complete control of an organisation changing it is in fact impossible.

And remember that the RN began in 1939 with almost nothing in terms of support. They received 4 airfields in Britain. They had to plan for how they could support what they had around the world, let alone the expansion that was already in the pipeline for the new carriers then building. So you find papers in the archives in the first half of 1939 about new facilities at home and abroad for repair & maintenance of naval aircraft. That is in addition to looking at aircraft production numbers, the numbers of slots on carriers and projections through until 1942 under various scenarios.

Aircraft acquisition policy is just one aspect and one where the RN was probably least experienced because that had been reserved to the RAF and Air Ministry, and defended jealously. Forming new staff requirements for everything needed, including aircraft, was the responsibility of the Directorate of Air Material created in Jan 1938. And you very rarely design and get a new aircraft into production in 18 months. So what do you do until you can decide exactly what you want? Just cancel everything in the pipeline? Or continue with what is already planned until you are clear about the new direction of travel? And by late 1939 the Admiralty had concluded that a new direction had to be found for its fighters. Hence all the confusion with industry as to what was actually being sought to fulfill N.8/39 and N.9/39.

There is an saying "act in haste, repent at leisure". And yes there is a balance to be struck and it would have been nice to have had things go faster. But everyone was working to a schedule that didn't foresee a war in Europe until about 1944. That included Hitler. The way things snowballed from Autumn of 1938 was just not in anyone's plans.

Well the truth is that for the USN, IJN and the RN the battleship was king throughout the inter-war period and everyone was focussed on how to destroy those of the enemy. The carrier was simply an enabler to allow that to happen. But the tactics used as a means of enabling were different because the circumstances faced by each navy were different and for the USN changed over time.

Between the wars the USN planning for a war against Japan was based around War Plan Orange which involved an advance across the Pacific to break the blockade of the Philippines. In the 1920s the carriers were closely linked to the battle fleet. By the 1930s, the carriers would operate individually and independently of the battle fleet, each with its own cruiser escorts, to firstly locate an enemy fleet and secondly to destroy his carriers to stop them from finding the US fleet. So firstly reconnaissance / scouting which while essential was difficult (Fleet Problem XI in 1930. 4 days of futile searching by both sides!). And the weapon to disable/destroy the enemy carriers grew to be the dive bomber (which itself grew out of hanging bombs on fighters). And fighters were to try to ensure that an enemy did not get the first hit in on its own vulnerable carrier i.e. attempting to control the airspace above their own ship within the limitations of the day. The spotting function was moved entirely to floatplanes on cruisers and battleships because the carriers were operating independently away from the battle fleet. As I noted the expectation for the USN was that its carriers would probably very quickly be disabled/destroyed. For a time in the early 1930s the USN virtually abandoned the torpedo bomber viewing it as ineffective.

War Plan Orange - Wikipedia

en.wikipedia.org

Using single carriers to attack places like Los Angeles and the Panama Canal, while spectacular, only served to demonstrate how vital it was to keep an enemy away from the vulnerable US coast. The real drive for USN carriers to attack land targets in the 1930s was to assist the Fleet in capturing enemy island outposts during a slow advance en route across the Pacific to relieve the Philippines and not "strategic" targets like the Panama Canal. And then the danger to them was the carrier strike aircraft being outranged by the land based variety or the same problem faced by the RN.

Inter war the RN expected to operate in much more confined waters under attack from land based bombers and outwith the range of the fighters of the day. And except against Japan wasn't going to encounter other carriers. So the role of the carrier could be much more focussed on attacking the enemy battle fleet. They weren't going to be supporting land campaigns or becoming involved in strategic bombing. Those were roles for the independent RAF, something not present in the USA. And the RN never lost faith in the torpedo, seeing it as the primary airborne weapon to at least slow down an enemy fleet. The purpose of the two seat fighters and later dive bombers was effectively flak suppression to allow the torpedo bombers to carry out that task.

Like the USN the RN did carry out annual exercises, usually with the Atlantic and Mediterranean Fleets in combination. They just didn't give them grand names like "Fleet Problem". And in those exercises they did seek to develop carrier tactics far beyond that achieved in 1918.

Night flying from carrier decks became a regular feature of FAA operations from the mid-1920s and explains why the FAA could carry out night operations from the earliest days of WW2. That necessitated development of appropriate flight deck lighting etc. From as early as 1928 Britain had begun to experiment with multi carrier forces. That had to include flying off, forming up concentration of aircraft for attack and orderly and safe return to the right ship. And they sought to use those multi carrier groups to seek out the enemy, not at sea, but where he thought he was safe, in his own ports. In 1932 for example the air groups from Courageous & Glorious combined to attack the Med Fleet in a Greek harbour (shades of Furious at Tondern in 1918 but on a far greater scale and a precursor to Taranto in Nov 1940 and Pearl Harbor in 1941). The IJN began multi carrier operations with the formation of the Kido Butai in April 1941 and the USN not until 1942.

Ah I hear the cry! If only they had bigger carriers in the first place. But what is better? A single flight deck that the USN expected to lose almost immediately or multiple decks offering an increased chance of survivability if only by splitting the attention of the attacking force?

So again we come back to different navies facing different threats, or perceiving the same threat in a different way, and having to formulate solutions to meet them. And really until the mid-1930s all nations are experimenting and developing carriers, the best types of aircraft to operate from them and the best tactics to employ. Yes from being the world leader at the end of WW1 the RN fell behind in carrier operations. But of the Big 3 carrier nations in WW2, it was the only one not to have full control of its naval air service during the inter-war period.

The Royal Navy never took attack by aircraft seriously and convinced itself, in cahoots with the RAF- that attacking ships at sea was too difficult except with torpedoes and low angle gunnery defences were more than adequate. Some did not agree, but they were siren voices quickly told to shut up.

Rear-Admiral [Aircraft Carriers] Sir Reginald G.H. Henderson , 1932

'the primary defense of the fleet against air attack [by gunfire] is not justified by data or experience. No realistic firing against aircraft has taken place since the last war and, in my opinion, the value of our own High Angle Control System Mk I is rated too high. In common with others, we are apt to over-rate the capabilities of our own weapons in peacetime.'

These 'exercises' were laughable - highly choreographed, the 'air attack' would culminate with a Queen Bee drone to be launched off a cruiser to be duly despatched by the massed fires of the Fleet - or not as the case always was.
With the introduction of the new HACS anti aircraft gunnery directors in the 30's, (they were rubbish) the Home Fleet conducted an excise to validate the massively more lethal anti aircraft gunnery capability with the rapidly deteriorating situation in Europe.

For two and a half hours, the entire Home Fleet banged away at the circling Queen Bee with zero effect, eventually, fed up of all this, the Queen Bee lost its radio link and was last seen heading off to a quieter life over the horizon.

This exercise was declared a 'great success'.

Reluctant Poster · Jul 21, 2022

Macandy said:
The big advantage the USN possessed in the SBD was it had a good enough performance to act as a secondary fleet defence 'fighter' which was indeed one of its its secondary roles.
It was more than good enough to tangle with confidence with enemy bombers - and had a good ability to defend itself against fighter types. Its performance in the role was good enough to instil confidence in its pilots to 'have a go'.

It was tried in the fleet air defense function once at Coral Sea. The experiment was never repeated. It was used in ASW duties.

EwenS · Jul 21, 2022

Macandy said:
The Royal Navy never took attack by aircraft seriously and convinced itself, in cahoots with the RAF- that attacking ships at sea was too difficult except with torpedoes and low angle gunnery defences were more than adequate. Some did not agree, but they were siren voices quickly told to shut up.

Rear-Admiral [Aircraft Carriers] Sir Reginald G.H. Henderson , 1932

These 'exercises' were laughable - highly choreographed, the 'air attack' would culminate with a Queen Bee drone to be launched off a cruiser to be duly despatched by the massed fires of the Fleet - or not as the case always was.
With the introduction of the new HACS anti aircraft gunnery directors in the 30's, (they were rubbish) the Home Fleet conducted an excise to validate the massively more lethal anti aircraft gunnery capability with the rapidly deteriorating situation in Europe.

For two and a half hours, the entire Home Fleet banged away at the circling Queen Bee with zero effect, eventually, fed up of all this, the Queen Bee lost its radio link and was last seen heading off to a quieter life over the horizon.

This exercise was declared a 'great success'.

Yes the exercises were unrealistic but it seems that US exercises were no different. See the previous post by Shortaround6.

But the other side of the coin with those exercises, is that the battleship admirals convinced themselves that ships could absorb torpedo hits and still sail merrily on unaffected. In one trial in 1932 they estimated that Resolution's speed would only be reduced by 7 knots (30%) after being hit with 7 x 18" Mk.VIII (320lb TNT warheads) torpedoes launched from Blackburn Darts. If anyone had actually believed those results the air launched torpedo would have been abandoned then and there. Given the anti-shipping results from WW2 it is just as well that the air launched torpedo was retained and tactics developed to minimise attacking aircraft losses. Even the USN after virtually abandoning it as ineffective (Ranger was built with no torpedo storage) went back to it from 1935.

By 1939 the RN was reckoned to have the best AA weapons for dealing with dive bombers, in the shape of quad and octuple pom-poms and quad 0.5". But in practice even that proved inadequate.

And the solution that Admiral Henderson came up with only three years after your quote, while he was Third Sea Lord and Controller of the Navy, was not to push for more, and more capable fighters, but to shield the available strike force under armour to protect it from 500lb bombs delivered by dive bombers and from cruiser gunfire. And so the Illustrious class was born.

And that brings us back to just how, in the days of reliance on the Mk.1 eyeball and increasing aircraft attacking speeds in the 1930s so decreasing warning time, you control the available fighters. I've posted before about this. It is no good having fighters if neither they nor the ships in the fleet can't locate the attackers sufficiently early to stop them dropping bombs on your lovely ships. Viewed in that context the decision not to depend on fighters for defence is in fact quite logical. Come 1940 everything begins to change because radar arrives on the scene and better ship-aircraft communications lead to infinitely better interception capabilities. But then again you have the benefit of one tool that the Admirals of the time didn't - the retrospectroscope!

But you will continue to believe what suits you. USN good. RN bad. Or should it just be, judging from some of your posts on other threads, US good. Britain bad.

Shortround6 · Jul 21, 2022

EwenS said:
By 1939 the RN was reckoned to have the best AA weapons for dealing with dive bombers, in the shape of quad and octuple pom-poms and quad 0.5". But in practice even that proved inadequate.

The 40mm pom pom was the best gun available for most of the 1930s. The problem was not enough of them (the likely enemies were not going to attack in 2s and 3s to give the guns time to switch to new targets) and that as attack speeds went up the time to engage the targets went down. The 40mm pom pom was a bit short ranged which compounded the problem. Most data lists over estimate the effective range, not just of the 40mm pom pom but just about all light AA guns. The 40mm pom pom was fairly heavy for what it did.
The octuple mount was 15-16 tons while the octuple mount had a massive amount of fire most ships never got more than 4 until late in the war and early war cruisers were luck to get two. It could be overwhelmed with attacks that had relatively few planes.

EwenS said:
And the solution that Admiral Henderson came up with only three years after your quote, while he was Third Sea Lord and Controller of the Navy, was not to push for more, and more capable fighters, but to shield the available strike force under armour to protect it from 500lb bombs delivered by dive bombers and from cruiser gunfire. And so the Illustrious class was born.

And here is one of the disconnects.
The British were going to go to armored flight decks and AA guns to counter dive and level bombers. And they were going to mount quad and octuple pom poms to counter dive dive bombers.
But they abandoned the dive bomber almost as soon as they adopted it. They never finished off the Skua (fitted a dive bomber sight or system) before they even delivered the first production models and then didn't the dive bomber back until the Barracuda.

Somehow the RAF concluded that dive bombing would become obsolete in the late 30s (better level bomb sights?) and it was worthless to pursue while the RN tried to get more AA guns and fit armored flight decks? The FAA were the ones who brought it back but it took too long.

EwenS · Jul 21, 2022

Shortround6 said:
The octuple mount was 15-16 tons while the octuple mount had a massive amount of fire most ships never got more than 4 until late in the war and early war cruisers were luck to get two. It could be overwhelmed with attacks that had relatively few planes.

Depends on the ship. The old battleships got 2-4 during the 1930s as they refitted /reconstructed. While KGV & PoW began with 4 the rest of the class started with 6. All were AA upgunned later in the war.

Ark was designed for 6 octuple mounts but didn't get the final port side pair until Aug 1941. Illustrious class were fitted with 6 from the start. Implacables with 5 and a quad. It was the quad that was more generally fitted in cruisers (with a few exceptions like Edinburgh & Belfast)

Shortround6 said:
And here is one of the disconnects.
The British were going to go to armored flight decks and AA guns to counter dive and level bombers. And they were going to mount quad and octuple pom poms to counter dive dive bombers.
But they abandoned the dive bomber almost as soon as they adopted it. They never finished off the Skua (fitted a dive bomber sight or system) before they even delivered the first production models and then didn't the dive bomber back until the Barracuda.

No. They didn't pursue the Fighter Dive Bomber represented by the Skua (to Spec O.27/34 issued Dec 1934), but they did pursue the dive bomber concept.

In July 1936 they issued Spec O.8/36 for a Dive Bomber Reconnaissance aircraft to Operational Requirement OR.36 capable of carrying 2x500lb SAP or 4x250lb SAP. That was quickly followed up in Sept 1936 with Spec M.7/36 for a Torpedo Spotter Reconnaissance Aircraft to succeed the Swordfish. Both those Specs were combined into Spec 41/36 issued in Feb 1937 to meet Operational Requirement 45. That Spec was to cover the Fairey Albacore which was on occasion used as a dive bomber during WW2, notably during Operation Torch.

That was then followed by Spec S.24/37 that produced a number of proposals of which Fairey & Supermarine were awarded contracts for prototypes (Barracuda and Type 322 "Dumbo" respectively) with Fairey getting a production contract in mid-1939.

Shortround6 said:
Somehow the RAF concluded that dive bombing would become obsolete in the late 30s (better level bomb sights?) and it was worthless to pursue while the RN tried to get more AA guns and fit armored flight decks? The FAA were the ones who brought it back but it took too long.

AIUI the RAF never wanted anything to do with dive bombing in the first place even after events in May/June 1940. Read a comment recently about the development of the Vultee Vengeance, that the order was placed in July 1940 by the Ministry of Aircraft Production (i.e. Beaverbtook) against the wishes of the RAF. There was even talk of them refusing to train the necessary aircrew for it.

Thumpalumpacus · Jul 21, 2022

SaparotRob said:
Didn't the RN come up with better fighter direction?

My understanding, and I'm certainly amenable to correction, is that the RN pioneered radar-vectoring of carrier-borne fighters, prior to any other navy in the world. If memory serves, one of the lessons the USN picked up from USS Robin was the more efficient use of radar in this mission.

Thumpalumpacus · Jul 21, 2022

Macandy said:
An excellent read, the US Navy entered WWII with a fully worked up and modern war winning carrier aviation doctrine.

Amazon product ASIN 178039392X

Fleet problem - Wikipedia

en.wikipedia.org

My reading indicates that while the USN certainly used carrier assets independently of the main fleet in a couple of Problems, even as late as 1941 the USN pegged its strategy on battleships, with carriers operating as adjuncts; and that this only changed due to the devastating losses at PH which forced the Gun Club to give carriers free rein. Am I wrong reading it this way?

As an aside, reading your link on the Fleet Problems, I notice none of them mention simulated attacks on PH, while many of the histories I've read mentioned those simulated attacks. Could someone steer me right on this?

EwenS · Jul 21, 2022

Thumpalumpacus said:
My understanding, and I'm certainly amenable to correction, is that the RN pioneered radar-vectoring of carrier-borne fighters, prior to any other navy in the world. If memory serves, one of the lessons the USN picked up from USS Robin was the more efficient use of radar in this mission.

The RN began radar directed fighter control on Ark Royal off Norway. Radar reports came in by light signal or radio from Valiant, one of the few radar equipped ships in the fleet, to be plotted by an officer sitting in the corner of the bridge with an Observer's Bigsworth Board to plot the reports. A telegraphist with him then directed the fighters in Morse Code. Initially the reports were advisory but as confidence built with successes they quickly became instructions.

An RN fighter direction school was opened in mid 1941 with participants pedalling converted ice cream carts around the airfield.

Pedal power at the Royal Naval Fighter Direction School, HMS Heron, Royal Naval Air Station, Yeovilton, Somerset – 1943

RICHARD MADDOX IN 1941 LIEUTENANT COMMANDER CHARLES COKE RN finished a tour of duty as Air Signals Officer on the aircraft carrier HMS Ark Royal – where part of his duties were directing figh…

iwmvolunteerlondon.wordpress.com

The first course included two USN officers. The USN got a look at things when Illustrious and Formidable were under repair at Norfolk from mid-1941. Then in Nov Indomitable arrived with the latest improvements and the fighter directors on all 3 ships got together to exchange notes. I've no doubt the USN sat in on that. Illustrious managed to get some RAF radar plotting equipment in early 1942 while in the IO.

The USN set up a fighter direction school around Sept 1941.

Formidable and Victorious were both refitted with the latest Action Information Office set up just before Torch. And Victorious got a further upgrade in Jan 1943 (a vertical glass plotting board in the AIO) while at Norfolk before going to the Pacific. At that time her outfit was the most advanced in either navy. That was one of the two main reasons for her operating as a fighter carrier while there.

Thumpalumpacus · Jul 21, 2022

EwenS said:
The RN began radar directed fighter control on Ark Royal off Norway. Radar reports came in by light signal or radio from Valiant, one of the few radar equipped ships in the fleet, to be plotted by an officer sitting in the corner of the bridge with an Observer's Bigsworth Board to plot the reports. A telegraphist with him then directed the fighters in Morse Code. Initially the reports were advisory but as confidence built with successes they quickly became instructions.

An RN fighter direction school was opened in mid 1941 with participants pedalling converted ice cream carts around the airfield.

Pedal power at the Royal Naval Fighter Direction School, HMS Heron, Royal Naval Air Station, Yeovilton, Somerset – 1943

RICHARD MADDOX IN 1941 LIEUTENANT COMMANDER CHARLES COKE RN finished a tour of duty as Air Signals Officer on the aircraft carrier HMS Ark Royal – where part of his duties were directing figh…

iwmvolunteerlondon.wordpress.com

The first course included two USN officers. The USN got a look at things when Illustrious and Formidable were under repair at Norfolk from mid-1941. Then in Nov Indomitable arrived with the latest improvements and the fighter directors on all 3 ships got together to exchange notes. I've no doubt the USN sat in on that. Illustrious managed to get some RAF radar plotting equipment in early 1942 while in the IO.

The USN set up a fighter direction school around Sept 1941.

Formidable and Victorious were both refitted with the latest Action Information Office set up just before Torch. And Victorious got a further upgrade in Jan 1943 (a vertical glass plotting board in the AIO) while at Norfolk before going to the Pacific. At that time her outfit was the most advanced in either navy. That was one of the two main reasons for her operating as a fighter carrier while there.

E EwenS , you are a goldmine. Thank you!

Shortround6 · Jul 21, 2022

EwenS said:
Depends on the ship. The old battleships got 2-4 during the 1930s as they refitted /reconstructed. While KGV & PoW began with 4 the rest of the class started with 6. All were AA upgunned later in the war.

Ark was designed for 6 octuple mounts but didn't get the final port side pair until Aug 1941. Illustrious class were fitted with 6 from the start. Implacables with 5 and a quad. It was the quad that was more generally fitted in cruisers (with a few exceptions like Edinburgh & Belfast)

I stand corrected on the larger ships but the cruisers were worse than I thought?
The US was no better with the 1.1in AA guns until the 1938-39 program ships appeared in 1941-42 and many of them were refitted very quickly.

EwenS said:
No. They didn't pursue the Fighter Dive Bomber represented by the Skua (to Spec O.27/34 issued Dec 1934), but they did pursue the dive bomber concept.

We have a difference of opinion here.

The Skua had dive brakes and could dive at fairly steep angle and hold it's dive using the dive brakes.
The idea was to use the constant speed dive at a constant angle to allow the pilot to "aim" the aircraft until the release point and the low speed, for a monoplane, would allow for a low release point also for accuracy.
The RAF had been working on a bombsight and in 3 years never finished it or a "bomb system" which would do several things depending on stage of development. While not the "automatic" system that Ju-87 used which pulled the aircraft into a pull out of a certain G and climb to altitude to ensure a safe pull out after releasing the bomb and while the pilot was blacked out (or nearly) the RAF was working on the automatic pull out upon bomb release or other aids like a flashing light on the ring and bead post to indicate the altitude at which to pull out. Nothing was approved.

The US dive bombers of the 1930s carried single 500lbs until the SBDs of 1940, with the larger 1000hp engines they got a 1000lb bomb.
The SBC-3 Biplane of which contract for 83 aircraft was signed in August 1936 and deliveries began on 17 July 1937. The production aircraft were powered by an 825 hp (615 kW) Pratt & Whitney R-1535-94. The aircraft had a bomb displacement swing located on the centerline of the fuselage for a 500-lb (227-kg) bomb or a 45-U.S.-gallon (170-liter) fuel tank.
The SBC-4 contract for 124 production aircraft of the XSBC-4 was signed on 5 January 1938 and deliveries began in March 1939 to April 1941. These used a 950hp Wright R-182o engine and could carry a 1000lb bomb.
The US dive bombers had a sight, it may not have been a fancy one and may have been little more than Aldis sight or a modification, but they had them.

The US was also planning, once the engines got powerful enough, to use 1000lb bombs and later larger.

The Swordfish and Albacore did not have dive brakes, being fixed landing gear biplanes they didn't need them. They weren't going to go very fast no matter what angle they dived at.
The British did allow for the carriage of large bomb loads under the wings but not the carriage of large single bombs, Although multiple 500lbs bombs was something the US could not do until the SB2C.
The British often described "dive bombing" but that is more like a fighter dropping it's bombs in a dive.

My opinion is it is more than semantics.
A true dive bomber is going to have "aids" to help the pilot line up the target. It might be as basic as a few lines painted on the cockpit to help judge the angle, It may be a simple telescopic sight. It may may be a button or switch to activate a trim position or elevator setting to assist in pulling out. In may have more than one aid.
The USN was still in the ship killing business using dive bombers, or at least ship crippling business in 1940-41. They had several different types of 1000lb bombs, they had space in the magazines. they had at least some aiming aids. They had a training program.

The RAF had checked out and left the FAA to use small bombs or multiple medium bombs and no aiming aids. If you want to use AP (or SAP) bombs from dive bombers you have to drop them at a certain height and speed to get the penetration you want. Dropping them low and slow, even in a steep dive, will not get the penetration required on big, heavily armored ships. If you are going to be in the ship killing business you also need to carry ship killing bombs in your magazines.
There was more to dive bomb training that flying at the ground, often with no bombs, and practicing pulling out without hitting the ground. Yes the British had 11lb and 20lb practice bombs but what was the actual training program? Some of the 1930s British training was only live fire once or twice a year.

Once again, British crews performed near miracles using equipment they should not have had to use.
The FAA, once they could order their own aircraft went back to a single big bomb under a plane that had dive brakes. It didn't show up until

Many, many missions were flown by fighter bombers and described as dive bombing and many units got rather good at it.
Did they ever get as good accuracy results as true dive bombers on small targets?

Ans some dedicated dive bomber designs turned out to not as good as hoped.

EwenS · Jul 22, 2022

You seem very hung up about the RAF decision not to pursue an automatic bomb sight for the Skua. Let's go back to some basics. What aiming equipment did each type have.

Ju87
The Wiki article draws heavily on Manfredo Griehl's 2001 book about the Stuka. AIUI the attack method was to set the aircraft up for the dive, including setting the bomb release height in the automatic pull out device. The target was selected via a window in the fuselage floor. The pilot then put the aircraft into a dive using red lines on the cockpit window to select the dive angle. Aiming was done manually by the pilot via the cockpit gunsight (same one as used for sighting the guns), which from cockpit photos appears to be a reflector sight of some kind. The automatic pull out system then indicated when dropping height was reached by flashing a light in the cockpit. Then the pilot pressed the bomb release. That did 2 things:-
1. Drop the bomb.
2. Activate the automatic pull out.

So throughout the process the accuracy is down to the pilot, not any automatic system. If the pilot is incapacitated on the way down and can't press the bomb release, plane and Mother Earth come together violently!

SBD
The bombing accuracy again depends on the skills of the pilot. The only assistance he had was a 3x optical telescope, which "was considered an aid to dive bombing, but not a panacea." (Peter Smith, Douglas SBD Dauntless). A pilot did not put his eye to that until near the end of the final dive to make final adjustments (which makes sense as otherwise it would be easy to lose sight of the target in the much narrower field of vision provided by a telescope). This device also had a problem when bombing from 16,000-18,000ft as it tended to fog up at around 7,000ft. That forced crews to bomb from lower altitudes. It was eventually cured by special optical coatings on lens and windscreen (Eric Brown noted that windscreen heating only became available on the SBD-5). Not even any lines on the cockpit windows to help him with the dive angle.

Note he has no aiming assistance, not even a ring and bead sight, until the moment he puts his eye to that telescope. That telescope was also the gunsight for use with the forward firing armament.

SBD pilots saw the introduction of a Mk.VIII reflector sight in 1943 as a great step forward. And a reflector sight was also fitted to the SB2C Helldiver.

Skua, Swordfish and Albacore
The Skua was fitted with a reflector sight from the outset i.e. matching the Ju87 fit. The latter pair made do with a standard ring and bead sight for use with the forward firing guns and as a bomb sight when dive bombing. The Barracuda introduced a more sophisticated reflector sight.

The Albacore was designed for diving at speeds up to 215 knots with flaps either up or down. The Swordfish would reach 200 knots in a dive "if the necessary considerable altitude was available". (Comments from Eric Brown in "Wings of the Navy"). So neither type required dedicated dive brakes, the drag from the biplane airframe being sufficient to limit diving speed.

Summary
The common theme to all these aircraft is that dive bombing accuracy was down, not to technology, but to the skill of the pilot in judging things like wind direction, ship movement and speed and ensuring the aircraft remained straight in a dive.

And very few dive bombers used 90 degree dives. Early Stuka operations did and Vengeance in Burma. USN policy was 70-75 degrees. Pre-war RN tests concluded "Steeper angles of dive give a far greater degree of accuracy, and it is suggested that an angle of not less than 65 degrees would be most advantageous." IJN Vals used 45-70 degrees, depending on the type of target being attacked.

Bomb size.
It is true that the RN stuck with the 500lb HE/SAP until 1944, even using them in asymmetrical loads under the wings of Barracuda Mk.II. (Designed for 4x500lb under the wings just like the Albacore but Mk.II/III were limited to carrying 3x500lb due to weight growth in the airframe). But where is the evidence that this was not adequate for the purpose for which they were intended? In the RN the dive bomber was for taking out A.A. crews on enemy ships and tearing up carrier decks. For the RN the ship killing / disabling weapon was always seen as the torpedo. Much more effort went into torpedo training and development of the necessary automatic sighting systems than dive bombing. And the British torpedo sight used from mid-war in the likes of Barracudas and Beaufighters was far more sophisticated that anything fielded by the USN.

It was only in 1944 that the RN obtained a supply of 1,600lb AP bombs from the US to hang under the fuselage of Barracudas, which had to be modified to carry them in that position. They were used with limited success against the Tirpitz (one bomb penetrated all her Armoured decks but then failed to explode and even then was found not to contain its full explosive charge). The next torpedo/dive bomber wasn't requested until 1943 and emerged as the Fairey Spearfish in 1945 with an internal bomb bay capable of toting up to 2,000lb of bombs or a torpedo but it never entered service.

The IJN wreaked havoc with the Val and its 250kg (550lb) bomb load, only moving to larger weapons in the Judy developed from 1938 which entered service in 1942.

So the US moved to 1,000lb bombs in 1938. Given the particular vulnerabilities of Japanese carriers to fire would using 500lb bombs made much of a difference? I don't think a single Japanese carrier was sunk by bombs alone. And the carriers were the principal targets of the dive bombers. And what therefore would be better, single large bomb hits or multiple smaller ones? But that is no doubt something that could be argued about all day without ever reaching a conclusion one way or the other so I'm content to leave that point there.

Fighter bombers as dive bombers
Did the achieve as good results as dedicated dive bombers? I came across a thread elsewhere recently praising the ability of fighters using dive bombing to drop bridges in Italy with great success. Units that were involved developed their own tactics to determine tip over points for example, often using markings on wings or cockpit canopies. Then aiming via the gunsight. In other words techniques no more sophisticated than dedicated dive bombers.

Finally you may be interested in this link article about the Skua

List of Skua pages

dingeraviation.net

And in particular one of its successes

Sinking of the Konigsberg

dingeraviation.net

ThomasP · Jul 22, 2022

Some additional information on the Albacore:
The flaps were normally used as dive brakes as they helped prevent the Albacore from exceeding its VNE.
In non-diving low speed flight it was found that the flaps and slats combination prevented a real stall, but they were normally not necessary for TO and landings.

EwenS · Jul 23, 2022

Thumpalumpacus said:
E EwenS , you are a goldmine. Thank you!

You might like this on U S developments.

The Beginnings of Naval Fighter Direction - Chapter 5 of Radar and the Fighter Directors

ethw.org

The first US air warning radars were 6 CXAM sets fitted to California (mid-1940 and moved to Hornet in 1942 when she arrived in the Pacific in place of her poorly performing SC set), Yorktown (Sept/Oct 1940), and cruisers Chester, Pensacola, Chicago and Northampton.

They were followed by 14 CXAM-1 sets of which 13 were fitted to Battleships (Texas, Pennsylvania, Washington, North Carolina & West Virginia), carriers (Wasp, Lexington, Saratoga, Ranger & Enterprise) and cruisers in 1941 with the final one on the seaplane tender Curtiss. The smaller SC set also began to appear before the end of the year with Hornet getting one of the first.

Frog · Jul 23, 2022

EwenS said:
....So the US moved to 1,000lb bombs in 1938. Given the particular vulnerabilities of Japanese carriers to fire would using 500lb bombs made much of a difference? I don't think a single Japanese carrier was sunk by bombs alone.....

MIDWAY !!!

EwenS · Jul 23, 2022

Frog said:
MIDWAY !!!

NO!!!

The US air attacks reduced the 4 carriers at Midway to little more than smoking wrecks but they were all still afloat and theoretically could have been saved. Damage control operations continued on all ships throughout the intervening period. The need for the escorting destroyers, tied up aiding them, for other purposes forced the Japanese into deciding to scuttle them.

Akagi - having been bombed around 10.26 on 4 June, she was still afloat the next morning. She was ordered to be scuttled. Japanese destroyers then fired 4 torpedoes into her (2 or 3 hits)

Kaga - bombed around 10.22 on 4 June and still afloat at 19.00. Ordered sunk by Japanese. 2 torpedoes from the destroyer Hagikaze sank her at 19.25.

Soryu - bombed 10.29 on 4 June. 19.12 the destroyer Isokaze was ordered to sink her and used 3 torpedoes to do so.

Hiryu - bombed 17.03 on 4 June after which she was still capable of 28 knots. Sunk at 05.20 the following morning by a single Japanese destroyer torpedo.

In the case of all 4 ships the bomb damage was largely confined to the areas of the hangar & flight decks. The machinery spaces had to be evacuated over time due to the tremendous fires above. But the hulls themselves were still intact. Not one single US torpedo attack succeeded that day.

The US was fortunate later in the war that it didn't face the same level of threat from IJN surface and air forces and was therefore able to tow damaged ships like Canberra, Houston, Reno and Franklin to safety. Franklin and Bunker Hill particularly suffered absolutely horrible fires but with intact hulls were able to be saved.

Reluctant Poster · Jul 23, 2022

Frog said:
MIDWAY !!!

Every fleet aircraft carrier lost in 1942, American or Japanese, was sunk by Japanese torpedoes. The sole exception was the Lexington which was scuttled by US torpedoes.
As for the Franklin the USN damage report admitted " It was fortunate that the tactical situation permitted the ship to be taken under tow and provided with a screen and air cover until out of the immediate danger zone." In other words the overwhelming strength of USN enabled the ship to be salvaged rather than scuttled.

Reluctant Poster · Jul 23, 2022

EwenS said:
You seem very hung up about the RAF decision not to pursue an automatic bomb sight for the Skua. Let's go back to some basics. What aiming equipment did each type have.

Ju87
The Wiki article draws heavily on Manfredo Griehl's 2001 book about the Stuka. AIUI the attack method was to set the aircraft up for the dive, including setting the bomb release height in the automatic pull out device. The target was selected via a window in the fuselage floor. The pilot then put the aircraft into a dive using red lines on the cockpit window to select the dive angle. Aiming was done manually by the pilot via the cockpit gunsight (same one as used for sighting the guns), which from cockpit photos appears to be a reflector sight of some kind. The automatic pull out system then indicated when dropping height was reached by flashing a light in the cockpit. Then the pilot pressed the bomb release. That did 2 things:-
1. Drop the bomb.
2. Activate the automatic pull out.

So throughout the process the accuracy is down to the pilot, not any automatic system. If the pilot is incapacitated on the way down and can't press the bomb release, plane and Mother Earth come together violently!

SBD
The bombing accuracy again depends on the skills of the pilot. The only assistance he had was a 3x optical telescope, which "was considered an aid to dive bombing, but not a panacea." (Peter Smith, Douglas SBD Dauntless). A pilot did not put his eye to that until near the end of the final dive to make final adjustments (which makes sense as otherwise it would be easy to lose sight of the target in the much narrower field of vision provided by a telescope). This device also had a problem when bombing from 16,000-18,000ft as it tended to fog up at around 7,000ft. That forced crews to bomb from lower altitudes. It was eventually cured by special optical coatings on lens and windscreen (Eric Brown noted that windscreen heating only became available on the SBD-5). Not even any lines on the cockpit windows to help him with the dive angle.

Note he has no aiming assistance, not even a ring and bead sight, until the moment he puts his eye to that telescope. That telescope was also the gunsight for use with the forward firing armament.

SBD pilots saw the introduction of a Mk.VIII reflector sight in 1943 as a great step forward. And a reflector sight was also fitted to the SB2C Helldiver.

Skua, Swordfish and Albacore
The Skua was fitted with a reflector sight from the outset i.e. matching the Ju87 fit. The latter pair made do with a standard ring and bead sight for use with the forward firing guns and as a bomb sight when dive bombing. The Barracuda introduced a more sophisticated reflector sight.

The Albacore was designed for diving at speeds up to 215 knots with flaps either up or down. The Swordfish would reach 200 knots in a dive "if the necessary considerable altitude was available". (Comments from Eric Brown in "Wings of the Navy"). So neither type required dedicated dive brakes, the drag from the biplane airframe being sufficient to limit diving speed.

Summary
The common theme to all these aircraft is that dive bombing accuracy was down, not to technology, but to the skill of the pilot in judging things like wind direction, ship movement and speed and ensuring the aircraft remained straight in a dive.

And very few dive bombers used 90 degree dives. Early Stuka operations did and Vengeance in Burma. USN policy was 70-75 degrees. Pre-war RN tests concluded "Steeper angles of dive give a far greater degree of accuracy, and it is suggested that an angle of not less than 65 degrees would be most advantageous." IJN Vals used 45-70 degrees, depending on the type of target being attacked.

Bomb size.
It is true that the RN stuck with the 500lb HE/SAP until 1944, even using them in asymmetrical loads under the wings of Barracuda Mk.II. (Designed for 4x500lb under the wings just like the Albacore but Mk.II/III were limited to carrying 3x500lb due to weight growth in the airframe). But where is the evidence that this was not adequate for the purpose for which they were intended? In the RN the dive bomber was for taking out A.A. crews on enemy ships and tearing up carrier decks. For the RN the ship killing / disabling weapon was always seen as the torpedo. Much more effort went into torpedo training and development of the necessary automatic sighting systems than dive bombing. And the British torpedo sight used from mid-war in the likes of Barracudas and Beaufighters was far more sophisticated that anything fielded by the USN.

It was only in 1944 that the RN obtained a supply of 1,600lb AP bombs from the US to hang under the fuselage of Barracudas, which had to be modified to carry them in that position. They were used with limited success against the Tirpitz (one bomb penetrated all her Armoured decks but then failed to explode and even then was found not to contain its full explosive charge). The next torpedo/dive bomber wasn't requested until 1943 and emerged as the Fairey Spearfish in 1945 with an internal bomb bay capable of toting up to 2,000lb of bombs or a torpedo but it never entered service.

The IJN wreaked havoc with the Val and its 250kg (550lb) bomb load, only moving to larger weapons in the Judy developed from 1938 which entered service in 1942.

So the US moved to 1,000lb bombs in 1938. Given the particular vulnerabilities of Japanese carriers to fire would using 500lb bombs made much of a difference? I don't think a single Japanese carrier was sunk by bombs alone. And the carriers were the principal targets of the dive bombers. And what therefore would be better, single large bomb hits or multiple smaller ones? But that is no doubt something that could be argued about all day without ever reaching a conclusion one way or the other so I'm content to leave that point there.

Fighter bombers as dive bombers
Did the achieve as good results as dedicated dive bombers? I came across a thread elsewhere recently praising the ability of fighters using dive bombing to drop bridges in Italy with great success. Units that were involved developed their own tactics to determine tip over points for example, often using markings on wings or cockpit canopies. Then aiming via the gunsight. In other words techniques no more sophisticated than dedicated dive bombers.

Finally you may be interested in this link article about the Skua

List of Skua pages

dingeraviation.net

And in particular one of its successes

Sinking of the Konigsberg

dingeraviation.net

I have posted a link to this video previously but it is worth reviewing again. According to this USN training video the ideal dive angle is 65 to 70 degrees.

EwenS · Jul 23, 2022

Just going through the Japanese carriers in WW2, other than the 4 lost at Midway:-

Hosho - survived

Ryujo - sunk Battle of Eastern Solomons 24 Aug 1942. Sunk by 3 or 4 x1,000lb bombs and a torpedo from aircraft off the Saratoga. Ship abandoned after an hour or so and subsequently capsized.

Shokaku - torpedoed by submarine Cavalla (3 hits) Battle of Philippine Sea 19 June 1944. Subsequently lost to fires and explosions caused by damage to her petrol tanks.

Zuikaku - sunk 25 October 1944 Battle off Cape Engano. Survived one attack with 1 torpedo and 3 bomb hits and drove off a second. Succumbed to 6 torpedo hits from a third attack.

Shoho - sunk Battle of Coral Sea 7 May 1942. Hit by 7 torpedos and 13 bombs within 30 mins.

Zuiho - sunk 24 Oct 1944. Battle off Cape Engano. Hit by two torpedos and multiple bombs with many more near misses causing additional underwater damage.

Hiyo - sunk 20 June Battle of the Philippine Sea. Lost to explosion following an earlier single torpedo hit and a bomb hit causing minimal damage to her bridge.

Junyo - survived, albeit damaged by submarine torpedo Dec 1944, and not repaired.

Ryuho - survived, albeit damaged by bombs while at Kure in March 1945, and not repaired.

Chitose - sunk Battle off Cape Engano 25 Oct 1944, to 3 large explosions - either near misses by bombs OR torpedo hits. No one seems sure.

Chiyoda - sunk Battle off Cape Engano 25 Oct 1944. Stopped by one bomb hit and several near misses. Eventually sunk by US 8" cruiser and destroyer gunfire when salvage attempts fail.

Taiho - lost to internal petrol explosion following being torpedoed by submarine Albacore 19 June 1944 during Battle of the Philippine Sea.

Shinano - torpedoed by submarine Archerfish.

Unryu - torpedoed by submarine Redfish

Amagi - damaged by bombs in air attacks while in port 19 March, 24 July (following which she was abandoned) and 28 July 1945 by both carrier aircraft and B-24s. Heavily damaged by both multiple hits and near misses, with many compartments flooded, she capsized on 29 July to become a total loss.

Katsuragi - damaged in air attacks by carrier aircraft on 19 March, 24 and 28 July she survived the war to be used as a repatriation transport.

The escort carriers Taiyo, Chuyo, Shinyo & Unyo were all torpedoed by US submarines and sunk. Kaiyo was damaged by air attacks by carrier aircraft of TF37 & 38 in various attacks in July 1945, after which salvage efforts stop, and by B-25s on 9 Aug, after which she was abandoned to settle on the bottom until salvaged and scrapped postwar.

The common factor to most the sinkings is that water had to get into the hull in large volumes. That was most likely to happen by large holes in the hull from torpedo hits.

Maybe the RNs concentration on torpedo attack instead of dive bombing is not as backward as sometimes suggested.

SaparotRob · Jul 23, 2022

Wonderful post, EwenS. I forgot about two of those. Chitose and Chiyoda. Not as bad as not remembering what plane Major Loften Henderson was flying. Could have sworn he was with the Vindicators.

EwenS · Jul 23, 2022

The only British carrier lost to dive bombing was the old and small Hermes off Ceylon on 9 April 1942, with only her limited AA armament to protect her.

The Japanese dispatched 85 Vals with 9 Zero escorts to deal with her, 79 armed with 250kg SAP and 6 with 250kg HE bombs. 45 targetted Hermes claiming 37 hits and 5 near misses in only a few minutes (British observers said "at least 40" hits). The remaining aircraft, seeing she was doomed, sought new targets claiming other vessels in the area.

Improved Skua for FAA?

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